This invention relates to a suspension control method and more particularly to a method for controlling suspensions by altering the damping force of shock absorbers installed in a suspension system of a vehicle.
Generally, a suspension is formed between a vehicle body (a sprung mass) and a wheel (an unsprung mass) to connect the body and the wheel and also to improve riding comfort by absorbing shocks to the vehicle body. Such a suspension generally includes a coil spring and a shock absorber for altering damping force so as to appropriately damp the vibration of the sprung mass.
In conventional suspension control method, the damping force of the shock absorber is altered in response to the driving condition of the vehicle for the purpose of improving maneuverability and riding comfort of the vehicle. For example, such suspension control methods have been introduced in prior arts as set forth below. One is "Air Suspension System" (Japan Unexamined Patent Application No. Sho 59-23712) wherein the characteristics of an air suspension are altered in response to the condition of the vehicle and the road surface. Another is "Damping Force Controller for a Shock Absorber Installed in a Suspension System of a Vehicle" (Japan Unexamined Patent Application No. Sho 59-120509) wherein the damping force of the shock absorber is set to a higher value when the vehicle goes around a curve so as to reduce the rolling rate and thus to decrease the overall rolling angle of the vehicle body, while on the other hand, when the vehicle returns to make a straight drive, the damping force is set to a lower value so as to restore the normal attitude of the vehicle.